/**
 * 判断是否 十六进制颜色值.
 * 输入形式可为 #fff000 #f00
 *
 * @param   String  color   十六进制颜色值
 * @return  Boolean
 */
export const isHexColor = (color: string) => {
    const reg = /^#([0-9a-fA-F]{3}|[0-9a-fA-f]{6})$/
    return reg.test(color)
  }
  
  /**
   * RGB 颜色值转换为 十六进制颜色值.
   * r, g, 和 b 需要在 [0, 255] 范围内
   *
   * @return  String          类似#ff00ff
   * @param r
   * @param g
   * @param b
   */
  export const rgbToHex = (r: number, g: number, b: number) => {
    // tslint:disable-next-line:no-bitwise
    const hex = ((r << 16) | (g << 8) | b).toString(16)
    return '#' + new Array(Math.abs(hex.length - 7)).join('0') + hex
  }
  
  /**
   * Transform a HEX color to its RGB representation
   * @param {string} hex The color to transform
   * @returns The RGB representation of the passed color
   */
  export const hexToRGB = (hex: string, opacity?: number) => {
    let sHex = hex.toLowerCase()
    if (isHexColor(hex)) {
      if (sHex.length === 4) {
        let sColorNew = '#'
        for (let i = 1; i < 4; i += 1) {
          sColorNew += sHex.slice(i, i + 1).concat(sHex.slice(i, i + 1))
        }
        sHex = sColorNew
      }
      const sColorChange: number[] = []
      for (let i = 1; i < 7; i += 2) {
        sColorChange.push(parseInt('0x' + sHex.slice(i, i + 2)))
      }
      return opacity
        ? 'RGBA(' + sColorChange.join(',') + ',' + opacity + ')'
        : 'RGB(' + sColorChange.join(',') + ')'
    }
    return sHex
  }
  
  export const colorIsDark = (color: string) => {
    if (!isHexColor(color)) return
    const [r, g, b] = hexToRGB(color)
      .replace(/(?:\(|\)|rgb|RGB)*/g, '')
      .split(',')
      .map((item) => Number(item))
    return r * 0.299 + g * 0.578 + b * 0.114 < 192
  }
  
  /**
   * Darkens a HEX color given the passed percentage
   * @param {string} color The color to process
   * @param {number} amount The amount to change the color by
   * @returns {string} The HEX representation of the processed color
   */
  export const darken = (color: string, amount: number) => {
    color = color.indexOf('#') >= 0 ? color.substring(1, color.length) : color
    amount = Math.trunc((255 * amount) / 100)
    return `#${subtractLight(color.substring(0, 2), amount)}${subtractLight(
      color.substring(2, 4),
      amount
    )}${subtractLight(color.substring(4, 6), amount)}`
  }
  
  /**
   * Lightens a 6 char HEX color according to the passed percentage
   * @param {string} color The color to change
   * @param {number} amount The amount to change the color by
   * @returns {string} The processed color represented as HEX
   */
  export const lighten = (color: string, amount: number) => {
    color = color.indexOf('#') >= 0 ? color.substring(1, color.length) : color
    amount = Math.trunc((255 * amount) / 100)
    return `#${addLight(color.substring(0, 2), amount)}${addLight(
      color.substring(2, 4),
      amount
    )}${addLight(color.substring(4, 6), amount)}`
  }
  
  /* Suma el porcentaje indicado a un color (RR, GG o BB) hexadecimal para aclararlo */
  /**
   * Sums the passed percentage to the R, G or B of a HEX color
   * @param {string} color The color to change
   * @param {number} amount The amount to change the color by
   * @returns {string} The processed part of the color
   */
  const addLight = (color: string, amount: number) => {
    const cc = parseInt(color, 16) + amount
    const c = cc > 255 ? 255 : cc
    return c.toString(16).length > 1 ? c.toString(16) : `0${c.toString(16)}`
  }
  
  /**
   * Calculates luminance of an rgb color
   * @param {number} r red
   * @param {number} g green
   * @param {number} b blue
   */
  const luminanace = (r: number, g: number, b: number) => {
    const a = [r, g, b].map((v) => {
      v /= 255
      return v <= 0.03928 ? v / 12.92 : Math.pow((v + 0.055) / 1.055, 2.4)
    })
    return a[0] * 0.2126 + a[1] * 0.7152 + a[2] * 0.0722
  }
  
  /**
   * Calculates contrast between two rgb colors
   * @param {string} rgb1 rgb color 1
   * @param {string} rgb2 rgb color 2
   */
  const contrast = (rgb1: string[], rgb2: number[]) => {
    return (
      (luminanace(~~rgb1[0], ~~rgb1[1], ~~rgb1[2]) + 0.05) /
      (luminanace(rgb2[0], rgb2[1], rgb2[2]) + 0.05)
    )
  }
  
  /**
   * Determines what the best text color is (black or white) based con the contrast with the background
   * @param hexColor - Last selected color by the user
   */
  export const calculateBestTextColor = (hexColor: string) => {
    const rgbColor = hexToRGB(hexColor.substring(1))
    const contrastWithBlack = contrast(rgbColor.split(','), [0, 0, 0])
  
    return contrastWithBlack >= 12 ? '#000000' : '#FFFFFF'
  }
  
  /**
   * Subtracts the indicated percentage to the R, G or B of a HEX color
   * @param {string} color The color to change
   * @param {number} amount The amount to change the color by
   * @returns {string} The processed part of the color
   */
  const subtractLight = (color: string, amount: number) => {
    const cc = parseInt(color, 16) - amount
    const c = cc < 0 ? 0 : cc
    return c.toString(16).length > 1 ? c.toString(16) : `0${c.toString(16)}`
  }
  
  // 预设颜色
  export const PREDEFINE_COLORS = [
    '#ff4500',
    '#ff8c00',
    '#ffd700',
    '#90ee90',
    '#00ced1',
    '#1e90ff',
    '#c71585',
    '#409EFF',
    '#909399',
    '#C0C4CC',
    '#b7390b',
    '#ff7800',
    '#fad400',
    '#5b8c5f',
    '#00babd',
    '#1f73c3',
    '#711f57'
  ]
  